In vitro translation of B-cell stimulatory factor-1 in Xenopus laevis oocytes

B-cell stimulatory factor-1 (BSF-1) can be translated in vitro in Xenopus laevis oocytes. This activity is blocked by an antibody to BSF-1. The RNA species coding for BSF-1 activity sediments of approximately 8-9S and is separable from RNA coding for interleukin-2 activity which sediments at approximately 11.5S. Finally, the fact that BSF-1 can be translated in vitro confirms that functions attributed to BSF-1 do not depend on contamination with other biologically active molecules such as phorbol myristate acetate.